The invention relates to a method of manufacturing a cytodiagnostic brush assembly which may be utilized to recover cells from an affected part of a coeliac cavity by being passed through a portion of an endoscope which is adapted to be inserted in such cavity.
FIG. 1 illustrates a cytodiagnostic brush assembly 10 which is used with an endoscope 1. The endoscope 1 includes a portion 5 which is adapted to be inserted into a coeliac cavity and which is provided with a channel 8 for allowing passage of a treatment instrument therethrough. The cytodiagnostic brush assembly 10 is passed through the channel in use. Specifically, the endoscope 1 includes the portion 5 which is adapted to be inserted into a coeliac cavity, an operating end 6 located outside a physical body, an eyepiece assembly 7, and a riser member 9. The portion 5 includes a distal end 2, the bendable portion 3 and a flexible portion 4, all of which are formed of a flexible tubular member, and the riser member 9 is disposed in the distal end 2 to control the direction in which a treatment instrument is caused to project out of the distal end. The cytodiagnostic brush assembly 10 includes an operating wire 10a which extends through a resilient flexible tube 81 formed by a close pitch coil. The entire assembly is detachably mounted in the endoscope 1 by being passed through the channel 8. The cytodiagnostic brush assembly 10 includes a brush 10b formed at the free end of the operating wire 10a which projects out of the resilient flexible tube 81 so as to be directed into a coeliac cavity from the distal end 2 of the endoscope. The brush 10b is in the form of an oblong ring body along which a number of bristles 11 are attached for allowing the recovery of cells from the coeliac cavity.
As is well recognized, in use, the endoscope 1 is inserted into a coeliac cavity such as bronchus, stomach or colon for purpose of observation and diagnosis of an affected part therein. While not shown, it should be noted that the distal end 2 of the portion 5 of the endoscope is provided with an observation window and an illumination window. To facilitate the insertion of the portion 5 into a coeliac cavity and to facilitate the observation and diagnosis of an affected part, the bendale portion 3 can be bent in a controllable manner and the flexible portion 4 is constructed to be a pliable assembly which can be flexed resiliently.
When the portion 5 of the endoscope 1 is inserted into a coeliac cavity with its distal end 2 located opposite to an affected part, the cytodiagnostic brush assembly 10 is driven forward to project the brush 10b out of the distal end 2 to be rubbed against the affected part in order to recover cell tissues thereof. The cytodiagnostic brush assembly 10 with recovered cell tissues is withdrawn, together with the resilient flexible tube 81, through the channel 8 to be taken out of the endoscope.
FIG. 2a shows a conventional construction of the cytodiagnostic brush assembly 10. As shown, it comprises an operating wire 10a extending straight forward and formed by twisting a pair of resilient strands together. A brush 10b, which is connected to the free end of the operating wire 10a, is formed by the pair of resilient strands which are shaped into an oblong ring with a number of bristles 11, of a material such as nylon, held between the strands so as to form a tortoise-shaped scrubbing brush. A short sleeve 12 clamps the free end of the strands forming the brush 10b together with the end of the operating wire 10a. Solder 13 is then injected into the clearance between the sleeve 12 and the operating wire 10a, between the sleeve 12 and the strands of the brush 10b, and between the operating wire 10a and the brush 10b. The solder 13 is shaped into a smooth profile to avoid the formation of any burr which may damage the internal wall of the coeliac cavity or the channel 8.
FIG. 2b shows another cytodiagnostic brush assembly 20 including a brush 20b which is formed by a pair of resilient strands twisted with bristles 21 held therebetween. A sleeve 22 is fitted over the free end of the strands of the brush 20b to cover and fix them, with solder 23 applied thereto and formed to present a smooth profile. The opposite end of the brush 20b is integrally formed with the straight operating wire 20a.
The cytodiagnostic brush assembly 10 or 20 thus formed may be used in the endoscope shown in FIG. 1 to project out of the flexible tube 81 so that the brush 10b or 20b may be used to recover cell tissues from an affected part of a coeliac cavity. The operating wire 10a or 20a of the cytodiagnostic brush assembly 10 or 20 extends through the flexible tube 81 and through the channel 8. The foremost portion of the wire is pliably bent by the riser member 9. It is formed of a hard, resilient strand material so that it may be strongly pulled in order to pass it through the flexible tube 81 formed by a close pitch coil or to operate the brush 10b or 20b without causing a permanent deformation of the wire.
In the construction of the conventional cytodiagnostic brush assemblies 10, 20 shown in FIGS. 2a and b, the sleeve 12 or 22 is fitted over the free end of the strands which define the brush, and solder applied thereto in order to cover and hold them in place. The solder must be formed or finished so as to present a smooth profile. Since the location where the solder is applied to the sleeve 12 or 22 is close to the bristles 11, 21, these bristles may be burned under heat from the soldering iron. Skill and an increased length of working time are required to prevent the bristles from being burned. To give a smooth profile to the solder, a special finishing operation must be performed, and the flux must be removed.